The present invention relates to mixtures of fluoroalkylphosphate salts and polymers, methods of producing same, and their use in electrolytes, batteries, capacitors, supercapacitors and galvanic cells.
In recent years, the spreading of portable electronic devices such as laptop and palmtop computers, cell telephones, or video cameras and thus, the demand for light-weight and high-performance batteries has dramatically increased worldwide.
In view of such rapidly increasing demand for batteries and the associated ecological problems, the development of rechargeable batteries having long service life and high performance has become more and more important.
More specifically, the quality of the electrolyte has an enormous effect on the service life and performance of the batteries, and the past therefore has seen numerous attempts of continuously improving the electrolyte.
Conventionally, the well-known electrolyte systems have been divided in liquid and solid electrolytes, and solid electrolytes comprise both polymer electrolytes and gel or hybrid electrolytes.
Battery cells based on liquid electrolytes generally have relatively good ionic conductivities, but are liable to leakage, giving rise to liberation of liquids which represent a potential hazard to man and environment. In addition, the production of such battery cells is restricted with respect to feasible sizes and shapes of these cells.
Polymer electrolytes normally are based on an optionally crosslinked polymer and a conducting salt. However, conventional polymer electrolytes frequently have low ionic conductivities which do not comply with the high demands to be met by modern batteries.
Gel or hybrid electrolytes are understood to be electrolyte systems including a solvent in addition to an optionally crosslinked polymer and a conducting salt. These polymers frequently are crosslinked at relatively high temperatures in the presence of the conducting salts. For this reason, appropriate conducting salts must have a relatively high thermal stability in solution because otherwise, they might undergo decomposition and in consequence, the ionic conductivity of the resulting gel electrolyte might be reduced.
DE 196 41 138 discloses lithium fluorophosphates having preferably per-fluorinated or partially fluorinated ethyl and isopropyl groups and their use as conducting salts in batteries. Use of these salts as conducting salts in polymer electrolytes has not been described. The German patent application, file number 100 08 955, describes lithium fluoroalkylphosphates and their use as conducting salts in batteries, capacitors, supercapacitors, and galvanic cells. There is no disclosure as to polymer electrolytes based on these salts.
The basic object of the present invention is to provide electrolytes which, in addition to high ionic conductivity, would have high thermal and electrochemical stability.
Another object of the present invention is to improve the service life and enhance the performance of batteries, capacitors, supercapacitors, and galvanic cells.
Surprisingly, these objects have been accomplished by providing mixtures including
a) at least one fluoroalkylphosphate salt of general formula (I)
Mn+([PFx(CyF2y+1-zHz)6-x]xe2x88x92)nxe2x80x83xe2x80x83(I)
xe2x80x83wherein
Mn+ is a univalent, bivalent, or trivalent cation,
1xe2x89xa6xxe2x89xa65,
1xe2x89xa6yxe2x89xa68, and
0xe2x89xa6zxe2x89xa62y+1, n=1, 2 or 3, and the ligands (CyF2y+1-zHz) each are the same or different, and
b) at least one polymer.
Mixtures in the meaning of the present invention include pure mixtures of components a) and b), mixtures wherein the salt of component a) is included in the polymer of component b), and mixtures wherein chemical and/or physical bonds exist between the salt of component a) and the polymer of component b).
Conventionally, corresponding mixtures comprised of at least one conducting salt and at least one polymer are also referred to as polymer electrolytes.
The mixtures according to the invention may also include two or more fluoroalkylphosphate salts of general formula (I) as component a) and/or two or more polymers of component b) at a time. Preferably, the mixtures of the invention each include a fluoroalkylphosphate salt of general formula (I) as component a) and a polymer of component b), because particularly good reproducibility of the electrochemical properties can be achieved in this way.
The mixture according to the invention preferably includes fluoroalkylphosphate salts of general formula (I) as component a), wherein Mn+ is a lithium cation, a sodium cation, a potassium cation, a rubidium cation, a cesium cation, a magnesium cation, or an aluminum cation. In a particularly preferred fashion, the mixture of the invention includes those salts as component a) wherein Mn+ represents a lithium cation.
Likewise, the mixture according to the invention preferably includes fluoroalkylphosphate salts of general formula (I) wherein Mn+ represents an organic cation. Preferably, the organic cation a nitrosyl cation, a nitryl cation, a tropylium cation, or a cation of general formula [NR4]+, [P(NR2)kR4xe2x88x92k]+, with 0xe2x89xa6kxe2x89xa64, [C(NR2)3]+, or [CR3]+, wherein each of the substituents R, same or different, represents
H,
CoF2o+1-pxe2x88x92qHpAq, or
A,
wherein
1xe2x89xa6oxe2x89xa610, 0xe2x89xa6pxe2x89xa62o+1, 0xe2x89xa6qxe2x89xa62o+1, preferably 1xe2x89xa6oxe2x89xa66, 0xe2x89xa6pxe2x89xa62o+1, 0xe2x89xa6qxe2x89xa62o+1, and A represents an aromatic residue optionally having hetero-atoms, or a preferably 5- or 6-membered cycloalkyl residue. The ligands CoF2o+1xe2x88x92pxe2x88x92qHpAq may also be at least partially substituted by chlorine and/or bromine, and the residues A may also be at least partially substituted by fluorine, chlorine and/or bromine.
All of the aromatic, heteroaromatic or cycloaliphatic compounds well-known to those skilled in the art and suitable in the preparation of [NR4]+, [P(NR2)kR4xe2x88x92k]30 , with 0xe2x89xa6kxe2x89xa64, [C(NR2)3]+, or [CR3]+ cations can be used as aromatic or cycloaliphatic residue A optionally including heteroatoms.
Preferably, A represents a 5- or 6-membered aromatic or cycloaliphatic residue optionally including nitrogen and/or sulfur and/or oxygen atoms, more preferably a phenyl or pyridine residue.
As component a), the mixtures according to the invention more preferably include fluoroalkylphosphate salts of general formula (I) having perfluorinated ligands, i.e., salts having ligands wherein 1xe2x89xa6xxe2x89xa65, 1xe2x89xa6yxe2x89xa68, and z=0.
In a particularly preferred embodiment of the present invention, the mixtures of the invention include one or more fluoroalkylphosphate salts as component a), which are selected from the group consisting of:
Li+[F6xe2x88x92xP(CF2CF3)x]xe2x88x92, with 1xe2x89xa6xxe2x89xa63,
Li+[F6xe2x88x92xP(CF2CF2CF3)x]xe2x88x92, with 1xe2x89xa6xxe2x89xa63,
Li+[F6xe2x88x92xP(CF2CF2CF2CF3)x]xe2x88x92, with 1xe2x89xa6xxe2x89xa63,
Li+[F6xe2x88x92xP(CF(CF3)2)x]xe2x88x92, with x=1 or 2,
[N(C2H5)4][PF3(C2F5)3],
[N(CH3)4][PF3(C4F9)3],
[P(N(CH3)2)4][PF3(C2F5)3],
[P(N(CH3)2)4][PF3(C4F9)3],
[P(CH3)4][PF3(C2F5)3],
[P(C2H5)4][PF3(C2F5)3],
[P(CH3)4][PF3(C4F9)3],
[P(C2H5)4][PF3(C4F9)3],
[C(N(CH3)2)3][PF3(C2F5)3], and
[C(N(CH3)2)3][PF3(C4F9)3].
The fluoroalkylphosphate salts of general formula (I) can be obtained using methods according to which at least one compound of general formula (II) to (VII)
HrP(CsH2s+1)3xe2x88x92r(II),
OP(CsH2s+1)3(III),
ClrP(CsH2s+1)3xe2x88x92r(IV),
FrP(CsH2s+1)3xe2x88x92r(V),
CltP(CsH2s+1)5xe2x88x92t(VI), and/or
FtP(CsH2s+1)5xe2x88x92t(VII),
wherein
0xe2x89xa6rxe2x89xa62,
3xe2x89xa6sxe2x89xa68, and
0xe2x89xa6txe2x89xa64,
is fluorinated by electrolysis in hydrogen fluoride, the mixture of fluorination products thus obtained is separated, and the fluorinated alkylphosphorane thus obtained is reacted in an aprotic solvent or solvent mixture under exclusion of moisture with a compound of general formula (VIII)
Mn+(Fxe2x88x92)nxe2x80x83xe2x80x83(VIII),
wherein Mn+ and n have the meanings as mentioned above. If necessary, the fluoroalkylphosphate salt of general formula (I) thus obtained can be purified and isolated according to conventional methods well-known to those skilled in the art.
Preferably, the electrolysis is performed at a temperature of from xe2x88x9220 to +40xc2x0 C., more preferably from xe2x88x9210 to +10xc2x0 C., and from xe2x88x925 to +5xc2x0 C. being particularly preferred. Preferably, the pressure is from 0.5 to 3 bars, more preferably from 0.5 to 1.5 bars, with normal pressure being particularly preferred.
The voltage applied during electrolysis preferably is from 4 to 6 V, more preferably from 4.5 to 5.5 V, the current density is from 0.2 to 5 A/dm2, more preferably from 0.2 to 2 A/dm2, and from 0.5 to 1.5 A/dm2 being particularly preferred.
Prior to electrolysis in hydrogen fluoride, the compounds of general formula (IV) and/or (VI) may also be reacted with inorganic fluorination agents, preferably with SbF3, SbF5, MoF5, VF5, or mixtures of at least two of these fluorination agents, thereby replacing the chlorine atoms by fluorine atoms. The reaction conditions used to perform such fluorinations are well-known to those skilled in the art.
Preferably, the reaction of the fluorinated alkylphosphoranes with a compound of general formula (VIII) is carried out at a temperature of from xe2x88x9235 to 60xc2x0 C., more preferably from xe2x88x9220 to 50xc2x0 C., and from xe2x88x9210 to 25xc2x0 C. being particularly preferred.
Preferably, carbonates, nitrites, ethers, esters, amides, sulfones, or mixtures of at least two of these solvents are used as solvents in the reaction of the fluorinated alkylphosphoranes with a compound of general formula (VIII).
As component b), the mixture according to the invention preferably includes a homopolymer or copolymer of unsaturated nitrites, preferably acrylonitrile, vinylidenes, preferably vinylidene difluoride, acrylates, preferably methyl acrylate, methacrylates, preferably methyl methacrylate, cyclic ethers, preferably tetrahydrofuran, alkylene oxides, preferably ethylene oxide, siloxane, phosphazene, alkoxysilanes, or an organically modified ceramic, or a mixture of at least two of the above-mentioned homopolymers and/or copolymers and optionally at least one organically modified ceramic.
Preferably, inorganic-organic hybrid polymers are possible as organically modified ceramics, which polymers are obtained by hydrolysis and fusion of organically modified silicon alkoxides and subsequent crosslinking of the crosslinkable groups fixed on the inorganic backbone. For example, appropriate organically modified ceramics are being marketed under the name of ORMOCERE(copyright).
In a preferred embodiment, the mixture according to the invention includes a homopolymer or copolymer of vinylidene difluoride, acrylonitrile, methyl (meth)acrylate, and tetrahydrofuran as component b). In a particularly preferred embodiment, a homopolymer or copolymer based on vinylidene difluoride is present as component b) polymer.
For example, these homo- and copolymers of vinylidene difluoride are being marketed under the names of Kynar(copyright) and Kynarflex(copyright) by Atofina Chemicals, Inc., and under the name of Solef(copyright) by the Solvay Company.
The polymers used according to the invention may also be at least partially crosslinked. Crosslinking can be effected according to conventional methods well-known to those skilled in the art, using well-known crosslinking agents. Crosslinking may also be effected in the presence of component a) and optionally additional components.
In a preferred embodiment of the present invention, the mixture includes from 5 to 99 wt.-% of component a) and from 95 to 1 wt.-% of component b), more preferably from 60 to 99 wt.-% of component a) and from 40 to 1 wt.-% of component b), each time relative to the sum of components a) and b).
In addition to the fluoroalkylphosphate salts of general formula (I) and the polymers, the mixture according to the invention may include a solvent or a mixture of solvents comprised of two or more solvents. Conventionally, such mixtures comprised of a conducting salt, a polymer and at least one solvent are also referred to as gel electrolytes.
Preferred solvents are organic carbonates, preferably ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, or methyl propyl carbonate, organic esters, preferably methyl formate, ethyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, xcex3-butyrolactone, organic ethers, preferably diethyl ether, dimethoxyethane, diethoxyethane, organic amides, preferably dimethylformamide or dimethylacetamide, sulfur-containing solvents, preferably dimethylsulfoxide, dimethyl sulfite, diethyl sulfite, or propanesultone, aprotic solvents, preferably acetonitrile, acrylonitrile, or acetone, or at least partially fluorinated derivatives of the above-mentioned solvents, or mixtures of at least two of these solvents and/or fluorinated derivatives of these solvents.
The present invention also is directed to a method of producing the mixtures of the invention, according to which at least one of the above-mentioned fluoroalkylphosphate salts of general formula (I) and at least one polymer and optionally at least one solvent are mixed together.
Preferably, the above components are mixed at elevated temperature, preferably at 20 to 90xc2x0 C., more preferably at 40 to 60xc2x0 C., and these temperatures may vary depending on the components employed.
The present invention is also directed to the use of at least one mixture of the invention in electrolytes, primary batteries, secondary batteries, capacitors, supercapacitors, and/or galvanic cells, optionally in combination with other well-known conducting salts and/or additives.
The invention is also directed to electrolytes, primary and secondary batteries, capacitors, supercapacitors, and galvanic cells including at least one mixture of the invention and optionally other conducting salts and/or additives. Other conducting salts and additives are known to those skilled in the art, e.g. fromDoron Auerbach, Nonaqueous Electrochemistry, Marc Dekker Inc., New York, 1999; D. Linden, Handbook of Batteries, Second Edition, McGraw-Hill Inc., New York, 1995; as well as G. Mamantov and A. I. Popov, Chemistry of Nonaqueous Solutions, Current Progress, VCH Verlagsgesellschaft, Weinheim, 1994. These citations are hereby incorporated by reference and are deemed to be part of the disclosure.
Likewise, the mixtures of the invention may include the fluoroalkylphosphate salts of general formula (I) in amounts of between 1 and 99 wt.-%, in combination with other conducting salts that find use in electrochemical cells. For example, conducting salts selected from the group of LiPF6, LiBF4, LiClO4, LiAsF6, LiCF3SO3, LiN(CF3SO2)2, LiC(CF3SO2)3, LiN(SO2C2F5)2, and Li[B(O4C2)2], and mixtures of at least two of these compounds are suitable.
In addition to the mixtures of the invention, these electrolytes may also include organic isocyanates (DE 199 44 603) to reduce the water content.
Compounds of general formula
[([R1(CR2R3)k]lAx)yKt]+(CF3)2Nxe2x88x92
wherein
Kt represents N, P, As, Sb, S, Se,
A represents N, P, P(O), O, S, S(O), SO2, As, As(O), Sb, Sb(O),
R1, R2 and R3, same or different, represent H, halogen, substituted and/or unsubstituted alkyl CnH2n+1, substituted and/or unsubstituted alkenyl having 1-18 carbon atoms and one or more double bonds, substituted and/or unsubstituted alkynyl having 1-18 carbon atoms and one or more triple bonds, substituted and/or unsubstituted cycloalkyl CmH2m+1, mono- or polysubstituted and/or unsubstituted phenyl, substituted and/or unsubstituted heteroaryl,
A may be included at different positions in R1, R2 and/or R3,
Kt may be included in cyclic or heterocyclic rings; the groups bound to Kt may be the same or different,
with
may also be included (DE 99 41 566). The method of preparing these compounds is characterized in that an alkali salt of general formula
D+(CF3)2Nxe2x88x92
with D+ selected from the group of alkali metals, is reacted in a polar organic solvent with a salt of general formula
[([R1(CR2R3)k]lAx)yKt]+Exe2x88x92
wherein
Kt, A, R1, R2, R3, k, l, x, and y have the above-stated meanings, and Exe2x88x92 represents Fxe2x88x92, Clxe2x88x92, Brxe2x88x92, lxe2x88x92, BF4xe2x88x92, ClO4xe2x88x92, AsF6xe2x88x92, SbF6xe2x88x92, or PF6xe2x88x92.
The mixtures according to the invention may also be included in electrolytes comprising compounds of formula
Xxe2x80x94(CYZ)mxe2x80x94SO2N(CR1R2R3)2,
with
prepared by reacting partially fluorinated or perfluorinated alkylsulfonyl fluorides with dimethylamine in organic solvents (DE 199 46 673).
Lithium complex salts of formula 
wherein
R1and R2 are the same or different, optionally bound directly to each other by a single or double bond, each one alone or together representing an aromatic ring from the group of phenyl, naphthyl, anthracyl or phenanthryl, which may be unsubstituted or from mono- to hexasubstituted by alkyl (C1-C6), alkoxy groups (C1-C6), or halogen (F, Cl, Br), or each one alone or together representing an aromatic heterocyclic ring from the group of pyridyl, pyrazyl or pyrimidyl, which may be unsubstituted or from mono- to tetrasubstituted by alkyl (C1-C6), alkoxy groups (C1-C6), or halogen (F, Cl, Br), or each one alone or together representing an aromatic ring from the group of hydroxybenzenecarboxyl, hydroxynaphthalenecarboxyl, hydroxybenzene-sulfonyl, and hydroxynaphthalenesulfonyl, which may be unsubstituted or from mono- to tetrasubstituted by alkyl (C1-C6), alkoxy groups (C1-C6), or halogen (F, Cl, Br), R3 to R6, each one alone or in pairs, optionally bound directly to each other by a single or double bond, may represent the following:
1. alkyl (C1-C6), alkoxy (C1-C6), or halogen (F, Cl, Br),
2. an aromatic ring from the groups of phenyl, naphthyl, anthracyl, or phenanthryl, which may be unsubstituted or from mono- to hexasubstituted by alkyl (C1-C6), alkoxy groups (C1-C6), or halogen (F, Cl, Br), pyridyl, pyrazyl or pyrimidyl, which may be unsubstituted or from mono- to tetrasubstituted by alkyl (C1-C6), alkoxy groups (C1-C6), or halogen (F, Cl, Br), prepared using the following method (DE 199 32 317)
a) 3-, 4-, 5-, 6-substituted phenol in a suitable solvent is added with chlorosulfonic acid,
b) the intermediate from a) is reacted with chlorotrimethylsilane, filtrated and subjected to fractionated distillation,
c) the intermediate from b) is reacted with lithium borate tetramethanolate in a suitable solvent, and the final product is isolated therefrom,
may also be included in the electrolyte.
Electrolytes having complex salts of general formula (DE 199 51 804)
Mx+[EZ]x/yyxe2x88x92
wherein
x, y represent 1, 2, 3, 4, 5, 6, Mx+ represents a metal ion, E represents a Lewis acid selected from the group of BR1R2R3, AIR1R2R3, PR1R2R3R4R5, AsR1R2R3R4R5, VR1R2R3R4R5, R1 to R5, same or different, optionally bound directly to each other by a single or double bond, each one alone or together may represent a halogen (F, Cl, Br), an alkyl or alkoxy residue (C1-C6) which may be partially or completely substituted by F, Cl, Br, an aromatic ring from the group of phenyl, naphthyl, anthracyl, or phenanthryl, optionally bound via oxygen, which may be unsubstituted or from mono- to tetrasubstituted by alkyl (C1-C6) or F, Cl, Br, an aromatic heterocyclic ring from the group of pyridyl, pyrazyl or pyrimidyl, optionally bound via oxygen, which may be unsubstituted or from mono- to tetrasubstituted by alkyl (C1-C8) or F, Cl, Br, and Z represents OR6, NR6R7, CR6R7R8, OSO2R6, N(SO2R6)(SO2R7), C(SO2R6)(SO2R7)(SO2R8), OCOR6,
wherein
R6 to R8 are the same or different, optionally bound directly to each other by a single or double bond, each one alone or together representing hydrogen or having the meaning like R1 to R5, prepared by reacting an appropriate boron or phosphorus/Lewis acid/solvent adduct with a lithium or tetraalkylammonium imide, methanide or triflate, can also be used.
Borate salts (DE 199 59 722) of general formula 
wherein
M represents a metal ion or a tetraalkylammonium ion, x, y represent 1, 2, 3, 4, 5, or 6, R1 to R44, same or different, represent alkoxy or carboxy residues (C1-C8) optionally bound directly to each other by a single or double bond, may also be included.
These borate salts are prepared by reacting lithium borate tetraalcoholate or a 1:1 mixture of lithium alcoholate and a boric acid ester in an aprotic solvent with a suitable hydroxy or carboxy compound at a ratio of 2:1 or 4:1.
Additives such as silane compounds of general formula
SiR1R2R3R4
with R1 to R4 H,
CyF2y+1xe2x88x92zHz,
OCyF2y+1xe2x88x92zHz,
OC(O)CyF2y+1xe2x88x92zHz,
OSO2CyF2y+1xe2x88x92zHz,
and
1xe2x89xa6xxe2x89xa66,
1xe2x89xa6yxe2x89xa68, and
0xe2x89xa6zxe2x89xa62y+1,
and
R1-R4, same or different, representing an aromatic ring from the group of phenyl, naphthyl, which may be unsubstituted or mono- or polysubstituted by F, CyF2y+1xe2x88x92zHz or OCyF2y+1xe2x88x92zHz, OC(O)CyF2y+1xe2x88x92zHz, OSO2CyF2y+1xe2x88x92zHz, N(CnF2n+1xe2x88x92zHz)2, or representing a heterocyclic aromatic ring from the group of pyridyl, pyrazyl or pyrimidyl, each of which may be substituted by F, CyF2y+1xe2x88x92zHz or OCyF2y+1xe2x88x92zHz, OC(O)CyF2y+1xe2x88x92zHz, OSO2CyF2y+1xe2x88x92zHz, N(CnF2n+1xe2x88x92zHz)2 (DE 100 27 626), may also be included.
The mixtures according to the invention may also be used in electrolytes including salts of formula
Li[P(OR1)a(OR2)b(OR3)c(OR4)dFe]
wherein
0xe2x89xa6a+b+c+dxe2x89xa65, and a+b+c+d+e=6, and R1 to R4 independently are alkyl, aryl or heteroaryl residues, and at least two of R1 to R4 may be bound directly to each other by a single or double bond (DE 100 16 801). These compounds are prepared by reacting phosphorus(V) compounds of general formula
P(OR1)a(OR2)b(OR3)c(OR4)dFe
wherein
0xe2x89xa6a+b+c+dxe2x89xa65, and a+b+c+d+e=5, and R1 to R4 have the above-stated meanings, with lithium fluoride in the presence of an organic solvent.
Ionic liquids of general formula
K+Axe2x88x92
wherein
K+ represents a cation selected from the group of 
wherein
R1 to R5 are the same or different, optionally bound directly to each other by a single or double bond, each one alone or together representing the following:
H,
halogen,
alkyl residue (C1-C8) which may be partially or completely substituted by F, Cl, N(CnF(2n+1xe2x88x92x)Hx)2, O(CnF(2n+1xe2x88x92x)Hx), SO2(CnF(2n+1xe2x88x92x)Hx), CnF(2n+1xe2x88x92x)Hx, with 1 less than n less than 6, and
0 less than xxe2x89xa613, and
Axe2x88x92 represents an anion selected from the group of
[B(OR1)n(OR2)m(OR3)o(OR4)p]xe2x88x92
with 0xe2x89xa6n, m, o, pxe2x89xa64, and
m+n+o+p=4, wherein
R1 to R4 are different, or pairs thereof are the same, optionally bound directly to each other by a single or double bond, each one alone or together representing an aromatic ring from the group of phenyl, naphthyl, anthracyl, or phenanthryl, which may be unsubstituted or mono- or polysubstituted by CnF(2n+1xe2x88x92x)Hx, with 1 less than n less than 6, and 0 less than xxe2x89xa613, or halogen (F, Cl, Br), or representing an aromatic heterocyclic ring from the group of pyridyl, pyrazyl or pyrimidyl, which may be unsubstituted or mono- or polysubstituted by CnF(2n+1xe2x88x92x)Hx, with 1 less than n less than 6, and 0 less than xxe2x89xa613, or halogen (F, Cl, Br), or representing an alkyl residue (C1-C8) which may be partially or completely substituted by additional groups, preferably F, Cl, N(CnF(2n+1xe2x88x92x)Hx)2, O(CnF(2n+1xe2x88x92x)Hx), SO2(CnF(2n+1xe2x88x92x)Hx), CnF(2n+1xe2x88x92x)Hx, with 1 less than n less than 6, and 0 less than x less than 13, or wherein
OR1 to OR4, each one alone or together, represent an aromatic or aliphatic carboxyl, dicarboxyl, oxysulfonyl, or oxycarboxyl residue which may be partially or completely substituted by additional groups, preferably F, Cl, N(CnF(2n+1xe2x88x92x)Hx)2, O(CnF(2n+1xe2x88x92x)Hx), SO2(CnF(2n+1xe2x88x92x)Hx), CnF(2n+1xe2x88x92x)Hx, with 1 less than n less than 6, and 0 less than xxe2x89xa613 (DE 100 26 565), may be included in the electrolyte.
Ionic liquids K+ Axe2x88x92 wherein K+ is as defined above and A represents an anion selected from the group of
[PFx(CyF2y+1xe2x88x92zHz)6xe2x88x92x]xe2x88x92
with
1xe2x89xa6xxe2x89xa66,
1xe2x89xa6yxe2x89xa68, and
0xe2x89xa6zxe2x89xa62y+1, may also be included (DE 100 27 995).
The mixtures according to the invention can be used in electrolytes for electrochemical cells including an anode material which consists of coated metal cores selected from the group of Sb, Bi, Cd, In, Pb, Ga, and tin, or alloys thereof (DE 100 16 024). The process for producing such anode material is characterized in that
a) a suspension or sol of the core metal or alloy in urotropine is prepared,
b) the suspension is emulsified with C5-C12 hydrocarbons,
c) the emulsion is precipitated on the metal or alloy core, and
d) the metal hydroxides or oxyhydroxides are converted to the corresponding oxides by tempering.
The mixtures according to the invention can also be used in electrolytes for electrochemical cells with cathodes made of common lithium intercalation and insertion compounds, but also with cathode materials consisting of lithium mixed oxide particles which are coated with one or more metal oxides (DE 199 22 522) by suspending the particles in an organic solvent, adding to the suspension a solution of a hydrolyzable metal compound and a hydrolyzing solution, and subsequently filtrating, drying and optionally calcining the coated particles. Said materials may also consist of lithium mixed oxide particles coated with one or more polymers (DE 199 46 066), obtained using a process wherein the particles are suspended in a solvent, and the coated particles subsequently are filtrated off, dried and optionally calcined. Likewise, the mixtures according to the invention can be used in systems including cathodes comprised of lithium mixed oxide particles having one or more coatings of alkali metal compounds and metal oxides (DE 100 14 884). The process for producing these materials is characterized in that the particles are suspended in an organic solvent, an alkali metal salt compound suspended in an organic solvent is added, metal oxides dissolved in an organic solvent are added, the suspension is added with a hydrolyzing solution, and the coated particles subsequently are filtrated off, dried and calcined. Likewise, the mixtures according to the invention can be used in systems including anode materials with doped tin oxide (DE 100 25 761). Such an anode material is prepared by
a) adding urea to a tin chloride solution,
b) adding the solution with urotropine and a suitable doping compound,
c) emulsifying the sol thus obtained in petroleum ether,
d) washing the resulting gel, and removing the solvent by suction, and
e) drying and tempering the gel.
Likewise, the mixtures according to the invention can be used in systems including anode materials with reduced tin oxide (DE 100 25 762). This anode material is produced by
a) adding urea to a tin chloride solution,
b) adding the solution with urotropine,
c) emulsifying the sol thus obtained in petroleum ether,
d) washing the resulting gel, and removing the solvent by suction,
e) drying and tempering the gel, and
f) exposing the resulting SnO2 to a stream of reducing gas in a gas-feedable oven.
The mixtures of the invention are advantageous because they do not show any sign of hydrolytic decomposition over a very broad temperature range. In addition to high thermal and electrochemical stability, they have high ionic conductivity.
By virtue of these properties, batteries, capacitors, supercapacitors, and galvanic cells including the salts or mixtures according to the invention can also be used under extreme conditions, such as high temperatures, with no adverse effects on their service life and performance by such conditions.
Furthermore, these batteries, capacitors, supercapacitors, and galvanic cells are remarkable for their highly constant voltage, unrestricted functionality over many charge/discharge cycles, as well as lower production cost.
The use of the mixtures of the invention in large batteries, such as those used in electric road vehicles or hybrid road vehicles is also highly advantageous, because no toxic and strongly etching hydrogen fluoride will be formed upon damage of the batteries, e.g. in case of an accident, not even upon contact with water, e.g. humidity or fire-fighting water.
With reference to the examples, the invention will be illustrated below. These explanations are merely by way of example and do not limit the general idea of the invention.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
In the foregoing and in the following examples, all temperatures are set forth uncorrected in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.
The entire disclosure[s] of all applications, patents, and publications, cited above [or below], and of corresponding German Application No. 10055812.7, filed Nov. 10, 2000, and German Application No. 10058264.8, filed Nov. 23, 2000 is hereby incorporated by reference.